Abstract: An implantable medical device that includes a microprocessor that characterizes cardiac activity of a patient to enable the implantable medical device to deliver therapy in response to an identified arrhythmia event. A monitor/controller monitors the characterized cardiac activity and the delivered therapy, and controls activation of triggered overdrive pacing subsequent to the delivered therapy.

Abstract: A system and method for creating lesions and assessing their completeness or transmurality. Assessment of transmurality of a lesion is accomplished by monitoring the depolarization signal amplitude in a local electrogram taken using electrodes located adjacent the tissue to be ablated. Following onset of application of ablation energy to heart tissue, the amplitude of a local electrogram measured with electrodes located adjacent tissue to be ablated first gradually drops and then stabilizes, indicating that the tissue being monitored has ceased making any contribution to the sensed electrogram. The amplitude drop and/or the following amplitude plateau may be used alone or together as indicators of transmurality. Detection of a rapid drop in amplitude may be employed as an indicator that the ablation process is proceeding too quickly and may be employed to trigger a reduction in the power of applied ablation energy.

Abstract: A system and method for creating lesions and assessing their completeness or transmurality. Assessment of transmurality of a lesion is accomplished by monitoring the impedance of the tissue to be ablated. Rather than attempting to detect a desired drop or a desired increase impedance, completeness of a lesion is detected in response to the measured impedance remaining at a stable level for a desired period of time, referred to as an impedance plateau. The mechanism for determining transmurality of lesions adjacent individual electrodes or pairs may be used to deactivate individual electrodes or electrode pairs, when the lesions in tissue adjacent these individual electrodes or electrode pairs are complete, to create an essentially uniform lesion along the line of electrodes or electrode pairs, regardless of differences in tissue thickness adjacent the individual electrodes or electrode pairs.

Abstract: A method for cardioverting or defibrillating a human heart, performed by placing a transvenous lead having a cardioversion or defibrillation electrode such that the electrode is located at least partially within the middle cardiac vein of a patient's heart and placing an additional cardioversion or defibrillation electrode in the superior vena cava of the patient's heart and thereafter delivering a cardioversion or defibrillation pulse between the first and second electrodes. The method may be practiced by placing the transvenous such that the defibrillation electrode it carries extends around the apex of the patient's heart, and the transvenous lead may be advanced through one cardiac vein toward the apex of the patient's heart and thereafter advanced upward through a different cardiac vein.

Abstract: A catheter assembly and method for treatment of cardiac arrhythmia, for example, atrial fibrillation, by electrically isolating a vessel, such as a pulmonary vein, from a chamber, such as the left atrium. The catheter assembly includes a catheter body and at least one electrode. The catheter body includes a proximal portion, an intermediate portion and a distal portion. The intermediate portion extends from the proximal portion and defines a longitudinal axis. The distal portion extends from the intermediate portion and forms a substantially closed loop transverse to the longitudinal axis. The at least one electrode is disposed along the loop. With this configuration, the loop is axially directed into contact with the chamber wall about the vessel ostium. Upon energization, the electrode ablates a continuous lesion pattern about the vessel ostium, thereby electrically isolating the vessel from the chamber.

Abstract: A catheter assembly and method for treatment of cardiac arrhythmia, for example, atrial fibrillation, by electrically isolating a vessel, such as a pulmonary vein, from a chamber, such as the left atrium. The catheter assembly includes a catheter body and at least one electrode. The catheter body includes a proximal portion, an intermediate portion and a distal portion. The intermediate portion extends from the proximal portion and defines a longitudinal axis. The distal portion extends from the intermediate portion and forms a substantially closed loop transverse to the longitudinal axis. The at least one electrode is disposed along the loop. With this configuration, the loop is axially directed into contact with the chamber wall about the vessel ostium. Upon energization, the electrode ablates a continuous lesion pattern about the vessel ostium, thereby electrically isolating the vessel from the chamber.

Abstract: A catheter assembly and method for treatment of cardiac arrhythmia, for example, atrial fibrillation, by electrically isolating a vessel, such as a pulmonary vein, from a chamber, such as the left atrium. The catheter assembly includes a catheter body and at least one electrode. The catheter body includes a proximal portion, an intermediate portion and a distal portion. The intermediate portion extends from the proximal portion and defines a longitudinal axis. The distal portion extends from the intermediate portion and forms a substantially closed loop transverse to the longitudinal axis. The at least one electrode is disposed along the loop. With this configuration, the loop is axially directed into contact with the chamber wall about the vessel ostium. Upon energization, the electrode ablates a continuous lesion pattern about the vessel ostium, thereby electrically isolating the vessel from the chamber.

Abstract: A system and method of making a lesion on living tissue including providing an electrosurgical system, determining a desired lesion depth, selecting a power setting, and applying electrical energy to the living tissue. The system includes an instrument having an electrode at a distal portion thereof, and a power source having multiple available power settings. The power source is electrically connected to the electrode. The step of applying electrical energy includes energizing the electrode at the selected power setting for a recommended energization time period that is determined by reference to predetermined length of time information and based upon the desired lesion depth and the selected power setting. The system preferably further includes a fluid source for irrigating the electrode at an irrigation rate. In this regard, the predetermined length of time information is generated as a function of irrigation rate.

Abstract: A method and system is provided for responding, from internally within a patient, to an atrial arrhythmia in a heart including measuring from within the patient at least one electrocardiogram characteristic indicative of the atrial arrhythmia, and controlling from within the patient drug therapy delivery to the patient responsive to measuring the at least one electrocardiogram characteristic. Drug therapy is initiated to the patient responsive to measuring the at least one electrocardiogram characteristic. According to one aspect of the present invention, the drug therapy is staged within the patient prior to measuring the at least one electrocardiogram characteristic. According to another example embodiment, the heart is paced from within the patient at a predefined rate responsive to measuring the at least one electrocardiogram characteristic, pacing occurring alone, or in combination with drug therapy.

Abstract: A method and system facilitates the access by a patient of implanted medical device related data for patient participation in their own clinical care and therapy. In an example embodiment, the method includes establishing a communications link between an implanted medical device and a data processor via an implanted medical device interface. Access to a secured database is obtained via the implanted device data processor using a set of patient identification data. A query is then submitted via the data processor to the secured database in response to input patient diagnostic data. Data received from the secured database is then displayed for use in a patient evaluation.

Abstract: The invention relates to the use of atrial pacing therapies to treat atrial tachycardia (AT). When an AT episode is detected, an implantable medical device applies an ATP therapy. If the AT episode persists, the ATP therapy may be automatically reapplied at a later time during the course of the same AT episode. In particular, previously used ATP therapies are reapplied when episodic conditions, such as cycle length or cycle regularity, change. Although a particular ATP therapy initially may be unsuccessful in terminating the AT, it may prove successful when the cycle length or regularity of the atrial rhythm changes. As the rhythm slows down, the AT may be more responsive to ATP therapies that were previously unsuccessful. As a result, potentially efficacious ATP therapies can be reapplied to terminate AT episodes, and reduce the number of episodes that require more aggressive termination by painful, atrial shocks.

Abstract: A catheter assembly and method for treatment of cardiac arrhythmia, for example, atrial fibrillation, by electrically isolating a vessel, such as a pulmonary vein, from a chamber, such as the left atrium. The catheter assembly includes a catheter body and at least one electrode. The catheter body includes a proximal portion, an intermediate portion and a distal portion. The intermediate portion extends from the proximal portion and defines a longitudinal axis. The distal portion extends from the intermediate portion and forms a substantially closed loop transverse to the longitudinal axis. The at least one electrode is disposed along the loop. With this configuration, the loop is axially directed into contact with the chamber wall about the vessel ostium. Upon energization, the electrode ablates a continuous lesion pattern about the vessel ostium, thereby electrically isolating the vessel from the chamber.

Abstract: A pain management system that enables a patient to control pain associated with the application of electrical therapies by an implanted device that includes using a non-implanted drug delivery device. In an example embodiment, a pain management system includes an implanted medical device that detects an arrhythmia of a heart and telemetrically communicates from the implanted medical device an arrhythmia condition. The system also includes an external drug delivery arrangement that receives telemetric communications on the arrhythmia condition from the implanted device and provides an alert of the arrhythmia condition to the patient. The external drug delivery arrangement communicates to the implanted device that a drug is being administered to the patient. The implanted medical device includes a capacitive circuit that delivers the electrical therapy to the heart in response to the drug being administered.

Abstract: A patient-controlled system for temporarily disabling an electrical cardioverting therapy in order to prepare the patient psychologically and physiologically for the pain associated with electrical cardioversion therapy. In an example embodiment, the system includes a capacitive circuit capable of charging and discharging in order to apply the electrical therapy. The implanted medical device automatically causes the capacitive circuit to charge and discharge at least once within a selected period. The system includes a patient activator device that communicates with the implanted device. A disabling circuit is also included within the implanted medical device that temporarily disables the electrical therapy application in response to the patient activator device. The system further includes an alerting arrangement that alerts the patient activator device in response to the disabling circuit.

Abstract: Notifying a patient or another person of an arrhythmia episode facilitates management of atrial fibrillation (AF) and other arrhythmias, including atrial flutter, atrial tachycardia, and supra ventricular tachycardia, thus enabling the patient to take corrective action even in the absence of symptoms or latent cardiac problems. For example, the patient may be prompted to take a medication, to initiate electrical therapy in the form of pacing or defibrillation, or to seek medical attention. Notification may be issued either by an implantable medical device or by an external device in communication with the implantable medical device. Various types of notifications may be issued under a variety of conditions, some of which may be associated with the duration of an episode.

Abstract: A device for ablating tissue is provided. The device comprises a conductive element with a channel for irrigating fluid formed therein, which is in contact with a non-conductive microporous interface. All or a portion of the interface may be removable. When the interface is removed, a portion of the conductive element is exposed for use in ablating tissue. Methods of using the device and of removing the interface are also provided.

Abstract: A method and apparatus are provided for protecting cardiac tissue from insult. The method comprises identifying the occurrence of an insult, such as a heart attack, and delivering electrical stimulation to one or more predetermined nerves in a patient's body in response to identifying the occurrence of the insult. The stimulation may be provided to peripheral nerves, intrinsic cardiac nerves, sympathetic ganglia, cranial nerves, and may generally be directed to the vertebral column, or within the chest wall of the patient.

Abstract: A system and method for creating lesions and assessing their completeness or transmurality. Assessment of transmurality of a lesion is accomplished by monitoring the impedance of the tissue to be ablated. Rather than attempting to detect a desired drop or a desired increase impedance, completeness of a lesion is detected in response to the measured impedance remaining at a stable level for a desired period of time, referred to as an impedance plateau. The mechanism for determining transmurality of lesions adjacent individual electrodes or pairs may be used to deactivate individual electrodes or electrode pairs, when the lesions in tissue adjacent these individual electrodes or electrode pairs are complete, to create an essentially uniform lesion along the line of electrodes or electrode pairs, regardless of differences in tissue thickness adjacent the individual electrodes or electrode pairs.

Abstract: A system and method for creating lesions and assessing their completeness or transmurality. Assessment of transmurality of a lesion is accomplished by monitoring the depolarization signal amplitude in a local electrogram taken using electrodes located adjacent the tissue to be ablated. Following onset of application of ablation energy to heart tissue, the amplitude of a local electrogram measured with electrodes located adjacent tissue to be ablated first gradually drops and then stabilizes, indicating that the tissue being monitored has ceased making any contribution to the sensed electrogram. The amplitude drop and/or the following amplitude plateau may be used alone or together as indicators of transmurality. Detection of a rapid drop in amplitude may be employed as an indicator that the ablation process is proceeding too quickly and may be employed to trigger a reduction in the power of applied ablation energy.

Abstract: A device for ablating tissue is provided. The device comprises a conductive element with a channel for irrigating fluid formed therein, which is in contact with a non-conductive microporous interface. All or a portion of the interface may be removable. When the interface is removed, a portion of the conductive element is exposed for use in ablating tissue. Methods of using the device and of removing the interface are also provided.